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Discussion Starter · #1 ·
hi guys, building the USS Voyager

anyway, i need to get the flight lights blinking away. but i'd like them to flash really fast once. then stay off for 2 seconds, then flash again, and go off for another 2 seconds.

i have a spare 555 chip around if that helps lol.

can anyone show me a circuit thats easy to follow so i can get this next part of my model done?
 

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LED flashers

I'd like to jump into this as well- I have a similar need. I am working on a 1/350 refit, and soldered up a blinker circuit using a 555 chip (sercretreeve-I can send you the schematic, only took a total amateur about 1 hour to make)- easy! In fact, I bought a range of capacitors to adjust the delay between blinks (the higher the capacitor the longer the delay).

But- here is my challenge that I need help with. The really, really nice lighting jobs have a "nav lights" cicuit that blinks red and green LEDs at a slower rate, and the LEDs stay lit a bit longer.

There is also a "fast circuit" that blinks white LEDs at a faster rate, and (here is the part I don't know) the LEDs stay lit for a much shorter time.

So the money question- how do I reduce the time an LED stays lit? I know how to manipulate the time in between the blinks. Thanks for the help!
 

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Goto "circuit help needed" thread for John F

Ok- that one pretty much answers your question and my question in one shot- note the whole thread- pretty much everything there, including the simple schematic I was using!

Good luck
 

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Discussion Starter · #8 ·
thats handy, just wouldnt know where to add in the leds to that circuit. also can i run the + and - wires for the led and split the end of that wire out to each led? or do they need to be in seriel/paralel?

because i have 17 leds in total which all need to go on/off at the same time/durations
 

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thats handy, just wouldnt know where to add in the leds to that circuit. also can i run the + and - wires for the led and split the end of that wire out to each led? or do they need to be in seriel/paralel?

because i have 17 leds in total which all need to go on/off at the same time/durations
http://www.voodoofx.com/

I had the impression you knew a little electronics, if you'd feel better buying a finished board I'd recommend talking with Randy at VoodooFX. But here is what needs to be added for driving more LEDs to the output of the 555 (pin3). 17 LEDs would draw about 400ma so the transistor should be rated for at least
an amp.
 

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Here is the simplest one I have seen yet- I have made two, one for the fast blink strobes and one for the slow-blink navs. The strobe can be fed with a 9V battery and I am powering 12 LEDs on this circuit.

The slow blink nav is also fed by 9V battery, has over 18 leds in series, both color and white and this circuit works like a champ!

The only difference is the capacitors uf rating.

Also on the scan are the exact Radio Shack product numbers, all were in stock at my local Shack. Sorry about the crappy writing, this is a working diagram that hung above my workshelf for a long time with hastily scribbled "lab notes" and an authentic soldering iron burn mark. Buy a 1.5" by 1.5" mini breadboard, they conveniently come in packs of two that one snaps apart.

All in all a few bucks and 1 hour with soldering iron. I will experiment with the suggestions from the other thread to see if I can get the time the strobes are lit down (not the time between blinks-this pretty darn close).

Note that the 110ohm resistor showing, I actually used 470 ohm resistors on all my LEDs.
 

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Discussion Starter · #13 ·
hmm found this on the forum



i guess i could run (for the first part of the circuit) a wire from the + and from pin 3 then do something like this

+ ______________________________________________________
| | | | | | | | | | | | | | | | | |
R R R R R R R R R R R R R R R R R R
L L L L L L L L L L L L L L L L L L
pin 3 |__|___|__|___|__|__|__|___|__|___|__|___|__|__|__|__|__|

erm...okay the forums edits out the spaces so thats a mess. but i think you get what i mean?

then do the same for the second part.

should work right?
 

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i guess i could run (for the first part of the circuit) a wire from the + and from pin 3 then do something like this

+ ______________________________________________________
| | | | | | | | | | | | | | | | | |
R R R R R R R R R R R R R R R R R R
L L L L L L L L L L L L L L L L L L
pin 3 |__|___|__|___|__|__|__|___|__|___|__|___|__|__|__|__|__|

erm...okay the forums edits out the spaces so thats a mess. but i think you get what i mean?

then do the same for the second part.

should work right?
The 555 can only drive about 200ma, 17 LEDs @ 20ma per would be 340ma.
you're going to need a transistor to drive your setup. Take a look at my post #10, you can run them in paralel with a one watt resistor if you'd like or have a resistor on each LED, that would give you a more uniform level of light from each LED. Just a thought.....
 

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Discussion Starter · #15 ·
hmm im having trouble with the post 10 because its only a part schematic.

i've already wired up the leds, resistors and wires to be put onto the circuit.

they have a 330ohm resistor on each led.

i know its a fair bit to ask, but i dont suppose you could do a full paint schematic?

i worked out the number of flashing leds is actually 12.

i quite like the timings on the one i posted, but would rather 1 second on, 2 seconds off.

also, which of the 2 parts on the one i posted controls the strobes?
 

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Teslabe- you mention that the 555 can only drive 200 ma. I have, on the nav circuit, 14 leds hooked in series to my 555 board on the schematic I attached below. I am driving it with 6 volts. Am I headed for a failure of some kind, and would it be the 555 that fails (which i can access and repair) or the LEDs that will fail ( which are sealed inside and cant be replaced).
 

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Teslabe- you mention that the 555 can only drive 200 ma. I have, on the nav circuit, 14 leds hooked in series to my 555 board on the schematic I attached below. I am driving it with 6 volts. Am I headed for a failure of some kind, and would it be the 555 that fails (which i can access and repair) or the LEDs that will fail ( which are sealed inside and cant be replaced).
Are you sure you have 14 LEDs in series? They wouldn't illuminate, even if they were red @ about 1.8v, you'd need 25.2 volts. If they are paralel, that would be about 280ma and you'd be pushing the output rating if your 555, that would be the part prone to fail. I think you forgot to post the schematic.....:wave: Is that the one in post#11?
 

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Could not have been said better! "Teslabe" is a very sharp with electrical design and build, take his advise he knows what he is talking about... Randy, Sorry for butting in!
Randy, happy to have you chime in.....:wave: I try to get the guys to talk with you about this stuff if it's a little over their heads, after all you do this for a living and offer the best price/customer support, IMHO.
 

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Hey teslabe- the schematic is the one I posted in #11. I pulled out my handy notes, and here goes what I have (every single LED has a 470 ohm resistor soldered to the LED):

Saucer-one run of wires via neck, and then going around counterclockwise- 1 white- 2 green, 2 whites, 2 reds, 1 white.

Into the main body- 1 white-2 white-1 white-2 yellow. Where there are 2 (a top and bottom) they are joined in parallel.

These two groups are twisted together right behind the main defector dish and a single set of wires goes to the 555 board

This board is hooked up to a radio shack 2.5 amp adaptor that has a slide that selects voltage from 6 to 12 volts. Sliding this slide make the lights brighter or dimmer (I like 6 volts the best). This adaptor also powers the strobe circuit (8 white via separate 555 board) and the main lights (several dozens as this lis lit Raytheon-style).

So, am I defying the laws of physics?

Richard
 
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